The invention relates to pharmaceutical compositions in the form of chewable tablets or chewable coated tablets which contain sucralfate as pharmaceutical active ingredient.
Sucralfate (Ulcogant.RTM.) is a basic aluminum sucrose sulfate. It is disclosed in DE-A 1,568,346 and is employed in human medicine for the therapy of duodenal ulcer and to prevent the recurrence thereof, of gastric ulcer and of reflux esophagitis. In addition, an advantageous action of sucralfate in the treatment of emesis and/or diarrhea in veterinary medicine is described in DE-A 3,322,078.
The action of sucralfate is primarily explained by pepsin-binding and antacid effects. Sucralfate is very well tolerated and displays its action in the acid medium of the digestive tract, especially at pH values below 4, in which case it coats the mucous membranes of the stomach and duodenum with a protective layer. A preferred binding capacity to areas of the mucous membrane which have been attacked provides increased protection there, resulting in an increased rate of ulcer healing and a regeneration of the mucous membrane and its functions.
Sucralfate-containing compositions have to date mainly been used in the form of solid dosage forms such as powders or granules which can be suspended in water, or in liquid dosage forms such as stable, non-sedimentable suspensions as are disclosed in DE-A 3,430,809. U.S. Pat. No. 4,684,534 also discloses sucralfate-containing tablets. Tablets or coated tablets which are swallowed unchewed cannot be employed in practice. The tablets which would be necessary are too large and are otherwise impossible to take because of the relatively high single dose of about one gram of active ingredient. When the tablets are smaller and have a correspondingly reduced amount of sucralfate, the number of tablets would have to be greatly increased in order to achieve the required daily dose. However, this is to be regarded as extremely inconvenient. Moreover, there is a continual dependence on water or beverages. The drug form which is simplest to take is tablets which can be slowly chewed or allowed to dissolve in the mouth. They have the advantage compared with granules or powders that liquid media can be dispensed with, and compared with ready-prepared suspensions, they save considerably more space and weight and thus can be transported considerably better.
However, chewable tablets or coated tablets have not to date been able to achieve market acceptance. The probable reason is evidently the fact that such tablets have an unpleasantly flat, irritating and sandy taste, even though relatively large amounts of water-soluble auxiliaries, especially sugar or sugar substitutes and flavorings, have been added to tablets or coated tablets, because of the sparing solubility of sucralfate. In addition, the requisite high content of water-soluble auxiliaries means that sucralfate-containing chewable tablets of the prior art often have a size, e.g., 2 grams and above, which is unacceptable, especially for children.